1、1,CHAPTER 6,2,Bond Stick On Ball(BSOB)/Bond Ball On Stitch(BBOS)/ Tail Break,3,1.0) BOND STICK ON BALL(BSOB),1.1) DescriptionThis bonding process is specially developed by ASM to handle multi-die(MCM) bonding application. In the conventional approach, if one is trying to connect the gold wire from o
2、ne die to the another, a capillary mark of second bond will be evident on top of the die which may damage the die. The BSOB process will solve this problem by bonding a ball onto the dies surface first, followed by bonding another wire where the second bonds wedge will be landing on top of this bond
3、ed ball(figure 1).,4,Die 1,Die 2,Bond Ball,2nd Bond(wedge),Figure 1 : Bond Stick On Ball(BSOB),5,2.0) BOND BALL ON STITCH(BBOS)/ SECURITY BOND,2.1) DescriptionThis process is also known as security bond. It bonds a ball on top of the wedge of the normal connection wire.This process is mainly used to
4、 secure the second bond sticking capability.(Figure 2),Die 1,Lead,Bond Ball,2nd Bond (wedge),Figure 2 : Bond Ball On Stitch (BBOS),6,3.1) Free Air Ball (FAB 2)is aligned to the center of the bond pad on device 2.,FAB 2,3.0 STANDOFF BALL CONTROL BONDING SEQUENCE,7,3.2) Capillary descends and bonds ba
5、ll to bond pad.,Device 1,Device 2,W/clamp open,Capillary,Application of 1st bond stand off ball parameter to form Ball Thickness and Ball Size,During Stand Off Bonding , SOB parameters are applied .,8,3.3) Capillary rises to loop base to clear ball.,Device 1,Device 2,W/clamp open,Capillary rises to
6、set Loop Base,Loop Base,Contact Pt.,Loop base is the distance between the capillary tip and contact point.,Recommended setting = 2,9,3.4) Capillary move to programme ball offset. Ball offset can be programmed towards or away from the first bond. + ve towards 2nd bond - ve away 2nd bond,Device 1,Devi
7、ce 2,Actual Ball Offset = Setting x 10um If Ball Offset Setting = 22 Then Actual Loop Base =220um,Recommended Setting = - ve 35,10,3.5) Capillary descends and forms stitch bond on top of the ball.,Device 1,Device 2,*Ball Thickness,SOB Parameter (Stand Off Ball Parameter),Capillary descends to set Ba
8、ll Thickness (Amt. Z movement above the ball height),Contact Pt.,* Ball Thickness is the distance between the capillary tip and contact point Recommended setting = 2,11,3.6) Capillary moves horizontally for a scrub distance to weaken the wire at ball neck.,Device 1,Device 2,Scrub one direction away
9、from ball,Actual Scrub Distance = Setting x 0.8 um If Scrub Distance Setting = 10 Then Actual Scrub Distance = 8 um,Capillary move to set Scrub Distance One direction ONLY - Away from the ball,Recommended setting = 8,12,3.7) Capillary rises to tail height,Device 1,Device 2,W/clamp close,Capillary mo
10、ves to set Tail Length (Amount Z movement above the bump before the wire clamp closes),Recommended setting = 35,13,3.8) Capillary rises and tears the wire, as BH ascend to Fire Level.,Device 1,Device 2,W/c close,14,15,3.10) After placing all standoff balls. The machine continue to bond wires.,2nd Bo
11、nd(wedge),Device1,Device2,Device1,16,Bump ball formation for BSOB/BBOS,MOTION,BO,LB,BT,SC,Normal LB BO BT Scrub,Flat LB BO BT Scrub=0,CONE LB BO BT=LB Scrub=0,LB,BO,BT,LB,BO,The bump ball formation process is almost like bonding a normal wire, including 1st bond, looping and 2nd bond parameters.,17,
12、4.0) PARAMETER DEFINITION IN STAND OFF BALL CONTROL MENU,4.1) Loop BaseThis parameter determines the loop level of the bondhead which should be sufficient to avoid the ball.Range: Loop Base 0 5Setting : 24.2) Ball OffsetThis setting controls the distance of the table move in order to offset the capi
13、llary from the standoff ball.Negative value can be moved towards to the first bond.Positive value can be moved away from the first bond.Range: Ball Offset - 40 20Setting : - ve 35,18,4.4) Scrub DistanceThis setting controls the capillary moves horizontally with a Scrub amplitude to weaken the wire a
14、t neck. It is always away from thefirst bond.Range: Scrub Dist 4 12Setting : 8 4.5) Tail LengthThis setting controls the length of the tail where the bondhead rises to the preset height before the wire clamp is closed. Range : Tail Length 30 40 Setting : 35,4.3) Ball ThicknessThis parameter refer to
15、 the ball thickness which controls the level of the bondhead as it descends to the top of the ballRange: Ball Thickness 0 5 Setting : 2,19,4.6) Time Base 1/2This setting controls the bond time applied to the standoff ball control only. Time 1 for the 1st bond and Time 2 for the 2nd bond.4.7) Power B
16、ase 1/2This setting controls the ultrasonic power applied to the standoff ball control only. Power 1 for the 1st bond and Time 2 for the 2nd bond.4.8) Force Base 1/2This setting controls the bonding force applied to the standoff ball control only. Force 1 for the 1st bond and Force 2 for the 2nd bon
17、d.,20,4.9) Standby Power 1/2This setting controls the power activated when the bonding head reach the search level, to the moment the bond head contacts the bond surface. With the vibration, before contact take place. Bond head will clean up the pad surface and remove water vapor on the pad. This pa
18、rameter used for the standoff ball control only.4.10) Contact Time 1/2Refer to the Contact time 1/2 definition in Bond Parameter menu. But this parameter will be affected on the Standoff ball control only.,21,4.11) Contact Power 1/2Refer to the Contact Power 1/2 definition in Bond Parameter menu. Bu
19、t this parameter will be affected on the Standoff ball control only.4.12) Contact Force 1/2Refer to the Contact Force 1/2 definition in Bond Parameter menu. But this parameter will be affected on the Standoff ball control only.,22,Figure 4 : Standoff Ball Control Parameter Display(page 2),5.0 BSOB W
20、IRE PARAMETERS,23,5.1) Wire Offset In -MenuThis is the offset parameter that is required to ensure maximum contact area between the stitch bond and ball. It is always away from the first bond.Range: Wire Offset 10 30 Recommended setting = 25,5.2) Second Bond Search SpeedThis Parameter controls the i
21、mpact for stitch on ball. Range: Search Speed 2 32 256Recommended setting = 32,2nd Bond Wedge,Stand Off Ball,Capillary position during stitch bond,24,5.3) Time Base 1/2This setting controls the bond time applied to the device. Time 1 for the 1stbond and Time 2 for the 2nd bond. 5.4) Power Base 1/2 T
22、his setting controls the ultrasonic power applied to the device. Power 1 for the 1st bond and Time 2 for the 2nd bond.5.5) Force Base 1/2 This setting controls the bonding force applied to the device. Force 1 for the 1st bond and Force 2 for the 2nd bond.,25,Ball Parameters for BSOB and BBOS,5.6 Tai
23、l Length Controls the length of the tail where the bond head rises to the preset height before the wire clamp is closed Range 15 45 (*10um),26,Ball Parameters for BSOB and BBOS,5.7 Tail break TimeUsed to increase the wire straightness and reduce the snake wire during BSOB/BBOS application Range 0 -
24、100 (*0.25ms) Setting 10,27,Ball Parameters for BSOB and BBOS,5.8 Tail Break DistanceUsed together with the tail break time Traveling distance can be determined by the setting Range 10 50 (*10um) Setting 25 Tail break time and tail break distance are valid only when the wire or ball tail break map in wire parameter menu is set to “Y”.,
